1. Field of the Invention
The present invention relates to information processing apparatuses that accumulate data such as image data, video data, audio data, and document data and that read out and display the data, and to methods for the same.
2. Description of the Related Art
Recently, the use of digital appliances, such as digital cameras, digital camcorders, digital audio players, digital video disk recorders, and flat-screen televisions, has been rapidly increasing. These digital appliances generate, accumulate, and reproduce (display) data such as image data, video data, audio data, and document data (hereinafter, collectively referred to as “contents”). Such contents are diverse, and an amount of the contents owned by an individual continues to increase.
To allow users to find a target content, information processing apparatuses generally display a list of contents. When there are many contents, the information processing apparatuses arrange the contents into a hierarchy to collectively handle a plurality of contents as a group using folders each having a name, thereby improving the findability. When a target content is not found using the folders, the information processing apparatuses find the target content by retrieving.
The above-described functions for arranging contents using folders and for retrieving the contents are suitable for content access performed in personal computers, namely, operations performed with a mouse and a keyboard. However, such functions are not necessarily suitable for operations performed with a television (hereinafter, abbreviated as a TV) and an infrared remote control (hereinafter, abbreviated as a remote control).
Accordingly, a function for sequentially displaying contents on a screen on the basis of a specified condition about a sorting order of a selected group of contents, such as, for example, all of the contents, only image contents, only video contents, or only audio contents, is known as a function suitable for content access performed with a remote control. For example, when users desire to see or listen to recently stored content, the users have only to press a button to sort all of the contents in a descending order of date and then sequentially view the contents using a “NEXT” button. In addition, when users desire to see a photograph captured in the last December, users switch a display mode to display the contents in a unit of month using an “EACH MONTH” button (in response to which, for example, a content representing that month is displayed) and select a target month. The users then press another button to sort the contents in a descending order of date and sequentially view the contents.
However, these functions require a sorting operation every time the sorting condition or the target group of contents is switched, which undesirably lowers the switching speed and decreases the usability. For example, the following two techniques for shortening a sorting time are known.
According to one technique, when song data is added to a library or when a memory card storing the song data is inserted to an information processing apparatus, the information processing apparatus sorts the song data in an order of the song title or the artist name and stores the sorting result. In response to an operation for displaying the song data in an order of the song title or the artist name, the information processing apparatus reads out the song data from the corresponding memory and displays the song data (Japanese Patent Laid-Open No. 8-235216).
According to another technique, an information processing apparatus sorts files recorded therein in response to addition or deletion of a file and stores the sorting result in a specific storage unit corresponding to each of sorting methods. In response to selection of a sorting method, the information processing apparatus reads out a file on the basis of the sorting result stored in the corresponding storage unit and displays the file (Japanese Patent Laid-Open No. 2004-30369).
However, since the above-described techniques used in the related art assume that a sorting-target group of contents is fixed, the above-described techniques are undesirably incapable of handling various requests entered through a user interface at the time of a content retrieval operation. The above-described techniques used in the related art do not consider a change of a sorting-target group of contents. Thus, the response speed to users operations and the operability undesirably decrease.